24 Replies Latest reply on Jan 30, 2010 3:17 AM by circle73

    Lossless JPEG rotation!  WTF?

    Mobius Strip Level 2

      This isn't a feature request; it's bug report.  Photoshop is demanding that you recompress JPEGs that have been rotated at 90-degree increments.  Other apps have been rotating JPEGs losslessly for almost a decade.

       

      INEXCUSABLE.

        • 1. Re: Lossless JPEG rotation!  WTF?
          ssprengel Adobe Community Professional & MVP

          If you're asking for this then you don't understand how PS works, where the reading, manipulation, and saving of files are distinct steps where the manipulation can be whatever you want. 

           

          Lossless rotation only applies when the reading, manipulation and writing are all combined into one step without being able to do other things to the image in between reading in and saving it.

          • 2. Re: Lossless JPEG rotation!  WTF?
            PECourtejoie Adobe Community Professional

            Yes, rotating in Bridge or Lightroom should do the job without a re-save. Photoshop is not the best tool for this job.

            • 3. Re: Lossless JPEG rotation!  WTF?
              c.pfaffenbichler Level 9

              INEXCUSABLE.

              Are You kidding?

              • 4. hm
                Mobius Strip Level 2

                "If you're asking for this then you don't understand how PS works"

                 

                Other image-manipulation programs with functionality very close to Photoshop's (the once-decent Paint Shop Pro comes to mind) are able to handle it.  Now granted, I do remember doing this mainly from the thumbnail browser in Paint Shop Pro; I don't know if that app retains the lossless capability as long as you don't manipulate the image in any way except rotation.  And that product has become such a turd that I'm unwilling to pollute my Windows installation with it to find out.

                 

                So really this comes back to the lack of an integrated browser in Photoshop, which has plagued the app for its entire existence.

                • 5. Re: hm
                  c.pfaffenbichler Level 9

                  I for one don’t find much merit in the original feature request.

                  It seems reasonable to me that if one opens a file in Photoshop and changes pixels the image will have to be saved in its entirety to keep those changes (and if one wants to apply a rotation as metadata there’s Bridge).

                   

                  Photoshop keeping track of what a user does and assessing if the changes were limited to metadata-conform operations might well be feasible but on what level such a feature would have to be implemented and what programming efforts or risks that would incur is certainly beyond me.

                   

                  As regards an integrated browser, I’m not sure I get what You are aiming for – something like Bridge without having to go there?

                  • 6. browser
                    Mobius Strip Level 2

                    "It seems reasonable to me that if one opens a file in Photoshop and changes pixels the image will have to be saved in its entirety to keep those changes"

                     

                    Of course.  But I didn't change any pixels.

                     

                    Photoshop should have a fast integrated browser.  You shouldn't have to launch a bloated external app and bounce back and forth between it and the other CS apps to open images.  Again, this is something that other apps have had for over a decade.  PSP's browser used to be excellent (now degraded), and way way back in the '90s there was a popular free app called Graphics Workshop (by Alchemy Mindworks) that featured a fast, lean thumbnail browser.

                     

                    PS didn't even have a browser until what, version 7?  After all that time and all the other examples of how it could and should be done, you'd think they would have been able to field a better product.

                    • 7. Re: Lossless JPEG rotation!  WTF?
                      JaZYsGOe

                      In the new version is easier ,I think.

                      • 8. Re: browser
                        c.pfaffenbichler Level 9

                        Of course.  But I didn't change any pixels.

                        Allow me some niggling: I consider the result of a rotation as a change of possibly every single pixel in an image (unless its a multiply symmetrical square image but then rotation would seem pointless).

                        • 9. zzz
                          Mobius Strip Level 2

                          Not really constructive, since the stated topic is lossless rotation and it's specifically called out in other apps and JPEG spec.

                          • 10. Re: zzz
                            c.pfaffenbichler Level 9

                            In which case I do apologize – I hadn’t read the Wikipedia-article on the JPEG-format that far, so I guess I have some more reading to do …

                            • 11. Re: zzz
                              Reynolds (Mark) Level 4

                              This whole thread poses a basic question   - why are you needing to rotate jpegs, without any other editing anyway? Are you so tight that you are as part of your workflow still exporting from your camera as jpeg?  - invest in a better hard drive, CF card, or at the very least, up the quality of your jpegs

                              • 12. Are you serious?
                                Mobius Strip Level 2

                                "why are you needing to rotate jpegs, without any other editing anyway? Are you so tight that you are as part of your workflow still exporting from your camera as jpeg?"

                                 

                                There are plenty of point-&-shoots that don't offer any other option.  And what if it's not YOUR workflow?  Have you never acquired pictures from other people, who not only use point-&-shoots but wouldn't know how to use anything else or even how to change their shooting mode?

                                 

                                And what about pictures that were taken in a nearly straight-up or straight-down orientation, where the camera's sensor can't determine which way is correct and will tag the image the wrong way?

                                 

                                There are many reasons you might need to rotate a JPEG.

                                 

                                And how would increasing the quality of JPEGs eliminate the need to rotate them?

                                • 13. Re: Are you serious?
                                  Gyno-jiz Level 5

                                  I think his point is that one rotation saved at max quality is just GIGO. No worries.

                                  • 14. Re: Are you serious?
                                    Reynolds (Mark) Level 4

                                    The problem remains: Unless you are, either incredibly tight on disk space, or frankly, in need of better file organisation: These days with cheaper memory - after you have opened the jpeg, and rotated the image, there is absolutely no reason to re-save onto your disk in jpeg format. Causing the additional damage.

                                     

                                    Whats happening WITHIN Photoshop, is that those artifacts are being non-destructively rotated, and then can be saved  losslessly. So the only damage to the image data is in the original compression artifacts - which you have no control over.

                                    • 15. no
                                      Mobius Strip Level 2

                                      I don't know why you're working so hard to convince everyone that there's no need for this.  If there were no need for this, you wouldn't find it in numerous other applications.

                                       

                                      "there is absolutely no reason to re-save onto your disk in jpeg format"

                                       

                                      Wrong.  I may want to E-mail it to someone, and a TIFF, PNG, PSD, or whatever may to be way too big.  Or I may be deploying it on some device that requires JPEG.  Really, who cares?  It's not for you to decide what everyone else's requirements are.

                                       

                                      The lossless rotation function for JPEG exists.  Arguing that we shouldn't use it and instead should bloat the files into some other format is dumb.  That takes time, in addition to disk space, and is simply POINTLESS.

                                      • 16. Re: no
                                        Reynolds (Mark) Level 4
                                        It's not for you to decide what everyone else's requirements are.

                                        Thats very true, point taken. Im still not sure in practice any of your examples hold up, but I'll leave it at that.

                                        • 17. Re: no
                                          Michael L Hale Level 5

                                          As I understand it NO program can resave a jpeg file after it has been opened and uncompressed without loss. The apps that do offer lossless rotation do so by editing the file directly without opening ( and there by don't need to uncompress and recompress ).

                                           

                                          I think that it would be a better request to have Bridge offer an option to rotate the file instead or in addtion to setting a flag in the XMP metadata.

                                          • 18. Re: no
                                            Level 5

                                            Michael L Hale wrote:

                                             

                                            As I understand it NO program can resave a jpeg file after it has been opened and uncompressed without loss. The apps that do offer lossless rotation do so by editing the file directly without opening ( and there by don't need to uncompress and recompress ).

                                            A file must be opened if something is rewritten to it.

                                             

                                            There are two ways in which lossless JPG rotation can occur. Michael may be thinking of a modification to the exif data that defines the orientation of the camera. This is basically a tweak to the header of a file and does not alter the primary image data. The other way is done by shuffling the minimum coded units (MCU). There's a decent demonstration here and a Photoshop plugin you can buy.

                                             

                                            Some of us use an image manager with this capability so we do not miss such ability in Photoshop. Through an image manager, you can select multiple thumbnails of turned images and upright them losslessly with one click. Photoshop, if it had the feature, would require you to open individual files, rotate, and then save them.

                                            • 19. Re: no
                                              Michael L Hale Level 5

                                              Yes, the file has to opened to do any modification to the file. Perhaps I should have said no program can resave a jpg file without loss after the file has been opened for image editing. i.e. the image data has been decompressed.

                                               

                                              Programs that do lossless rotation do by modifying the file without decompressing the image data and can only do so if the file meets certain requirements. Some jpg files can not be rotated without loss.

                                               

                                              Bridge writes the rotation to the XMP section of the file in the tiff rdf.

                                              • 20. Re: no
                                                Christian Davideck Level 1

                                                Michael L Hale wrote:

                                                 

                                                ... can only do so if the file meets certain requirements. Some jpg files can not be rotated without loss.

                                                 

                                                that's nonsense. Examples ?

                                                Post a .jpg file here and I'll re-post it here after a lossless rotation anytime you wish.

                                                • 21. Re: Are you serious?
                                                  Christian Davideck Level 1

                                                  Reynolds (Mark) wrote:

                                                   

                                                  ... after you have opened the jpeg, and rotated the image, there is absolutely no reason to re-save onto your disk in jpeg format. Causing the additional damage.

                                                   

                                                  Mark, the topic is lossless JPEG rotation. So yes, you can "re-save onto your disk in jpeg format" without "causing additional damage". And it would be stupid not to do so, if you only rotate the .jpg

                                                   

                                                  Mobius Strip wrote:

                                                   

                                                  The lossless rotation function for JPEG exists.  Arguing that we shouldn't use it and instead should bloat the files into some other format is dumb.  That takes time, in addition to disk space, and is simply POINTLESS.

                                                   

                                                  Exactly!

                                                  • 22. Re: no
                                                    Michael L Hale Level 5

                                                    From the JPEG FAQ

                                                     

                                                    In particular it is possible to do 90-degree rotations and
                                                    flips losslessly, if the image dimensions are a multiple of the file's
                                                    block size (typically 16x16, 16x8, or 8x8 pixels for color JPEGs).  This
                                                    fact used to be just an academic curiosity, but it has assumed practical
                                                    importance recently because many users of digital cameras would like to be
                                                    able to rotate their images from landscape to portrait format without
                                                    incurring loss --- and practically all digicams that produce JPEG files
                                                    produce images of the right dimensions for these operations to work.  So
                                                    software that can do lossless JPEG transforms has started to pop up.  But
                                                    you do need special software; rotating the image in a regular image editor
                                                    won't be lossless.

                                                     

                                                    If the image does not meet those width and height requirements it can not be rotated by any app without loss.

                                                    • 23. Re: no
                                                      Christian Davideck Level 1

                                                      Michael L Hale wrote:

                                                       

                                                      If the image does not meet those width and height requirements it can not be rotated by any app without loss.

                                                       

                                                      Okay Michael, this is getting redundant.You already mentioned "requirements". I asked for examples. Just post a .jpg file here that doesn't meet the "requirements" and thus can't be losslessly rotated, and I will try to do so nonetheless and re-post it here. Maybe I'll turn out to be wrong, who knows, but let's just try, that's much more interesting than copy/pasting theories ...

                                                      • 24. Re: Lossless JPEG rotation!  WTF?
                                                        circle73

                                                        In the new version is easier ,I think so.